The Lockheed aircraft RC-121D, which was also called the Lockheed aircraft, was a United States Air Force and United States Navy airborne early warning system that supplemented the Distant Early Warning Line. It came with two huge radomes, with one being horizontal located below the fuselage and the other, a vertical one, positioned on top of the aircraft. The aircraft was used for gathering intelligence (SIGINT). Introduced in 1984, the US Air Force and the US Navy used the Lockheed ECE-121...

The Lockheed aircraft RC-121D, which was also called the Lockheed aircraft, was a United States Air Force and United States Navy airborne early warning system that supplemented the Distant Early Warning Line. It came with two huge radomes, with one being horizontal located below the fuselage and the other, a vertical one, situatedpositioned on top of the aircraft. The aircraft was used for gathering intelligence (SIGINT). Introduced in 1984, the US Air Force and the US Navy used the Lockheed...

Based on the Lockheed Super Constellation, WV-2s served from 1956 to 1965 in two "barrier" forces, one off each coast of the North American continent. These barrier forces consisted of five surface picket stations each manned by radar destroyer escorts and an air wing of WV-2s that patrolled the picket lines at 3,000-12,000 foot altitudes in six to 20-hour missions. The Navy received 142 of the EC-121s produced. While barrier operations off the United States ended in 1965, the Navy continued...